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1.
植物群落对景观温度特征指示作用的研究   总被引:1,自引:0,他引:1       下载免费PDF全文
江源 《植物生态学报》2000,24(5):523-527
 以德国Kraichgau地区为研究样区,根据转化糖方法获得的野外实测温度数据,就植物群落温度平均指示值在景观尺度上对生境温度的指示效果进行了深入探讨。结果表明:1)群落温度平均指示值与测定的效应温度之间具明显线性正相关;2)群落温度平均指示值能够反映不同坡向条件造成的生境温度差异,但效果随计算方法不同而异。3种不同方法的比较结果说明,直接根据样方资料获得的计算结果,对坡向条件造成的生境温度差异反映明显;3)以样带数据为基础的研究结果对温度随坡向和坡位变化的反映均不够明显。样带没有达到足够的宽度以及样带中局部地段上的种类组成受人为影响严重可能是未达到预期对比效果的主要原因。  相似文献   

2.
利用光合菌发酵对玉米秸杆进行转化的研究*   总被引:2,自引:0,他引:2  
系统研究了光合菌在氨法处理和非氨处理两种环境下,在厌氧、好氧、以及自然条件下对玉米秸秆的转化。通过发酵液中还原糖与蛋白质浓度的测定结果的比较、判断、优选出一种最适合条件下光合菌对玉米转化的途径。研究表明,在以氨化法处理的玉米秸秆为底物与光合菌的发酵实验中,发酵液中的还原糖和蛋白质的尝试都要比非氨法条件下玉米秸秆为底物与光合菌发酵实验中的发酵液中的不原糖和蛋白质的浓度高。实验结果证明了转化产生的还原糖、蛋白质都是光合菌能利用的营养成分,由此达到利用光合菌转化玉米秸秆的研究目的。  相似文献   

3.
固定化酵母细胞连续生产转化糖反应动力学的研究   总被引:1,自引:1,他引:0  
利用海藻酸钠固定化面包酵母细胞,在搅拌罐和填充柱反应器内连续反应由蔗糖生产转化糖,对该过程的反应动力学研究结果表明;内,外传质阻力,转化酶活力、料液流量,搅拌速率和媒体半径对转化率有影响,本文给出了它们之间相互关系的数学表达式,本文还定义了阻力因子,动力因子及返混因子,并讨论了它们对转化效率所起的作用,给出了串联反应器操作的有关计算公式,测定了有关动力学参数,给出了料液流量控制,搅拌转速控制,媒体半径选择和最大转化率操作条件的计算方法,并在搅拌罐反应器、填充柱反应器和串联搅拌罐反应器中进行了实验和计算,从实验上验证了动力学理论研究结果。  相似文献   

4.
糖多孢红霉菌A226 的原生质体转化和染色体同源整合   总被引:15,自引:0,他引:15  
糖多孢红霉菌的原生质体转化和染色体同源整合,是红霉素生物合成基因改造的重要途径。本研究对糖多孢红霉菌A226原生质体制备和转化条件进行了优化,结果表明以对数生长后期和稳定期菌丝体制备的原生质体转化效率较高;质粒、原生质体和PEG-T缓冲液体积比例为15:40:200(μl)时转化效果较好;比重小原生本的转化效率虽高,但在转化子中有效整合的比例较低;PEG1000和PEG3350对转化效率没有显差异;而Yamamoto转化系统优于Weber转化系统。PCR鉴定、抑菌活性鉴定和质谱分析均表明,转化质粒已整合到染色体红霉素合成基因位点。  相似文献   

5.
本研究从哈茨木霉(Trichoderma harzianum) A25-2总RNA中利用RT-PCR的方法扩增到其纤维二糖水解酶I基因的cDNA序列,并对该基因编码的氨基酸序列进行分析,得到cbhI基因中编码催化功能域的序列。将催化功能域编码序列克隆到表达载体pCP-GH中,用PEG-CaCl2介导的原生质体转化方法将重组质粒转化到绿色木霉(Trichoderma viride) HP35-3中,筛选得到12个转化子。以p-NPC为底物,测定了该12个转化子的酶活力,获得比活力最高的转化子Tv/CDHl-CBM-5,其纤维二糖水解酶活力是HP35-3的3.8倍。SDS-PAGE分析表明,绿色木霉表达了导入的含A25-2纤维二糖水解酶I催化功能域的编码序列。  相似文献   

6.
稀有糖的生物转化生产策略:Izumoring方法   总被引:4,自引:0,他引:4  
稀有糖是在自然界中存在但含量极少的一类单糖及衍生物,其在膳食、保健、医药等领域中发挥着重要的功能。本文综述了一种稀有糖的生物转化生产策略----Izumoring方法,即利用D-塔格糖3-差向异构酶、醛糖异构酶和多元醇脱氢酶等进行所有单糖及糖醇之间的相互转化;利用该原则,分别构建了己糖类、戊糖类和丁糖类的Izumoring转化策略,并可获得所有稀有糖的酶反应和生物转化生产途径。同时,展望了稀有糖生物转化生产的研究趋势。  相似文献   

7.
介绍了一种用1-甲基咪唑为溶剂和催化剂、盐酸羟胺和乙酸酐为肟化和乙酰化试剂,对植物样品中糖与糖醇进行乙酰化衍生化后的气相色谱分离和质谱鉴定的分析方法。并对糖与糖醇乙酰化影响较大的反应温度、反应时间、反应物组成和反应物浓度等条件进行了比较研究,确定了糖与糖醇乙酰化各步反应的最佳反应温度和反应时间,分析了各组分间相互作用及其用量对衍生化效率的影响。对多种糖与糖醇乙酰化产物进行毛细管气相色谱分离、FID检测及GC-MS结构鉴定。研究证明, 在合适条件下应用此方法对糖与糖醇进行乙酰化,反应完全,产物单一,能得到理想的分离、检测和定量分析效果。适用于微量植物组织中多种单糖、双糖及其糖醇的定量分析。  相似文献   

8.
城市公园是城市生态系统的重要组成部分和城市生物多样性热点地区,具有丰富的声景观资源。由于声景观及声学方法具有信息量大,成本低,低侵入的特点,因此其研究和应用对生态系统健康及监测具有较高价值。声景观研究通过总结生物声的活动或多样性来衡量生物多样性。记录了北京20个城市公园的春季声景观,使用定量方法描述了声景观特征与变化;测试三种了已被证明与生物多样性相关并被广泛使用的声学指数(BIO、ADI、NDSI)与植被群落关系,完成了城市环境中声景观与环境关系的初步探究。研究结果表明:(1)声学指数能够有效表征城市公园声景观信息,具有显著的时间动态特性,能准确反映鸟类黎明合唱等重要生物生态活动;(2)声学强度指数也具有显著的时间动态变化和沿频率梯度的变化,不同的频率区间反映了不同声学群落的活动信息;(3)植被结构尤其是垂直结构对声景观起着重要作用,垂直异质性越大,声学多样性越高。发现支持声景观作为公园植被状况的度量,强调了其作为生物多样性和生态系统健康状况监测方法,用于城市管理和可持续发展的巨大潜力。  相似文献   

9.
为了优化利用N糖苷酶F(PNGase F)酶解单克隆抗体中N糖的方法,应用本公司生产的单抗对PNGase F酶的酶解条件进行优化,包括缓冲液pH、酶种类、仪器、酶解程度、变性缓冲液及酶加入量等,总结酶解条件对N糖谱结果的影响。结果显示,置换缓冲液至1×PBS中可以避免某些单抗在低pH酶解时G0F转化为G0F-GN并可改善峰型;快速PNGase F和加入变性缓冲液能有效提高酶解效率;UPLC和1.7 μm粒径色谱柱能提高分离度;不完全酶解影响N糖含量结果。研究结果表明,采用优化的酶解条件可快速、有效的酶解单抗上的N糖,使N糖谱结果准确可靠,为细胞株筛选和单抗药物质量控制提供有效手段。  相似文献   

10.
南亚热带森林种群分布格局取样技术研究   总被引:38,自引:0,他引:38       下载免费PDF全文
陆阳 《植物生态学报》1986,10(4):272-282
 森林群落中植物种群分布格局测定和分析的结果,密切依赖于野外取样的技术手段及资料的可靠性。本文通过鼎湖山自然保护区三个不同森林群落类型的取样,比较了随机样方、相邻格子样方、中心点四分法、最近相邻法和最近个体法在野外操作、数据整理以及种群分布格局测定分析中的效用,对各方法在南亚热带森林群落中进行种群分布格局研究中的适用性予以客观评价。研究表明,同一样地中不同取样方法和测定方法会导致不同结果。随机样方取样数据的测定结果受样方大小影响,而几种无样地方法在种类复杂的群落中,应用受到限制。相邻格子样方适用于各群落类型中种群分布格局的测定与分析。  相似文献   

11.
Soil temperature, texture, water content and sowing depth are effective factors on the estimation of emergence time. This research aimed to test the Beta model for its adequacy in predicting the time of emergence for sugar beet. The Beta growth model as a phenological model have been used for evaluating the time of seedling emergences under both controlled environments in laboratory and field conditions. An experiment was conducted both in the laboratory with five soil textures, three sowing depths, five soil water contents and ten constant soil temperatures, under field conditions on five sowing dates (20 February, 28 March, 19 April, 10 May, and 31 May) and three sowing depths. The results demonstrated that the Beta model can predict the time of emergence. Based on the root mean square error (RMSE), the time of emergence estimated by the Beta model was in high agreement with the time of emergence measured in the laboratory. Estimation accuracy was reduced slightly by the Beta model under field conditions. The accuracy of the Beta model was influenced by the sowing date under field conditions. So, on the first and second sowing dates (with low air temperature), the estimation of time of emergence by the model was lower and on the fourth and the fifth sowing date (with warmer air temperature), was more than the duration measured. Estimation accuracy was increased by the Beta model under field conditions using soil temperature. In conclusion, the Beta model can predict the time to emergence of sugar beet seedlings in different levels of soil texture and soil water content under field conditions, and with that, the proper planting date for sugar beet seeds to overcome weeds in different soil water content can be predicted.  相似文献   

12.
This contribution takes the notion of herbal landscape (a mental field associated with plants used to cure or prevent diseases and established within specific cultural and climatic zones) as a starting point. The authors argue that the features by which a person recognises the plant in the natural growing environment is of crucial importance for the classification and the use of plants within the folk tradition. The process of perception of the plant can be divided into analytical categories according to the sign concept of Charles Sanders Peirce. Whereas the plant can be seen as the object, the feature(s) the plant is recognised by is (are) the representamen(s), and the image of the plant within the herbal landscape can be understood as the interpretant. Different methods of perception of the signs within the herbal landscape are demonstrated comparing the herbal knowledge acquired from the herbals with the method of plant recognition learned in the traditional way. The first can be looked at with the terms of Tim Ingold as transportation, using plant features to go across, leaving all other signs present in the landscape unnoticed. The wayfarer, guided by signs learned within the context of surroundings, walks along and perceives the plant as a part of the herbal landscape. Although the examples analysed come from Estonian ethnobotany, the method of analysis can be applied in ethnobotanical research worldwide.  相似文献   

13.
A method suitable for the study of the physiology of absorptionof substances from solution and of respiration of Peltigerapolydactyla was elaborated making use of discs of tissue whichcould be floated on solutions. The rate of absorption of hexosesugars by the discs was sensitive to temperature, the presenceof inhibitors, such as sodium fluoride and silver nitrate, butrelatively insensitive to hydrogen ion concentration. Glucosewas absorbed preferentially to fructose from equimolar solutions.Absorption of sugar from sucrose solutions involved inversionby an enzyme system held on the cell surface. This system wasrelatively unaffected by exposure to moderate temperature, tosodium fluoride or silver nitrate but sensitive to hydrogenion concentration. Sucrose did not seem to be absorbed as suchand the glucose was absorbed preferentially from the productsof inversion. All parts of the thallus were equally effectivein inversion but absorption was mainly into the algal layer.The entry into the tissues was associated with a respiratoryrise.  相似文献   

14.
景观格局分异特征在相当程度上影响着城市热环境.本研究以国家森林城市龙泉市为对象,通过地温反演和空间分析反映9类景观温度特征,运用景观格局分析方法从1~3.5 km 6个尺度探索格局指数与热环境的相关性.结果表明: 龙泉市高温区及次高温区主要分布于东北至西南一带,以城乡居民地为主,低温区和次低温区主要分布于西北、东南区域,以公益林为主;对海拔700 m以下区域各景观类型地表温度的统计发现,针叶林地、阔叶林地、针阔混交林地、竹林地、水域的地温均值相对较低,灌木林地、其他林地、耕地、建设用地的地温均值相对较高;对景观格局与热环境的分析发现,类型水平格局指数较景观水平格局指数更具实际意义,建设用地与热环境的相关系数可达0.835,针叶林地、阔叶林地、针阔混交林地、水域次之,在-0.5~-0.4,不同林地类型的降温效果在空间尺度上的表达不同,阔叶林地、针阔混交林地更利于在大尺度上降温;林地的面积和蓄积量越大,越易出现地表温度低值.  相似文献   

15.
生态系统服务与景观格局集成研究综述   总被引:1,自引:0,他引:1       下载免费PDF全文
梁友嘉  刘丽珺 《生态学报》2018,38(20):7159-7167
生态系统服务是综合科学和政策应用的有效工具,可用于应对人类干扰下的景观和生态系统服务的快速退化等复杂生态环境问题。综述生态系统服务与景观格局集成的学科发展、基础理论和模型开发的进展与存在的问题,建立可用的集成建模框架,并提出知识集成的概念框架:1)在要素层,"政策-决策—景观—生态系统服务—社会经济系统"的跨学科知识反馈环是集成理论基础; 2)在模型层,结构化、多层次的集成模拟模型是核心方法; 3)在数据层,多源数据集成是模拟模型的数据基础。集成生态系统服务与景观格局为区域生态环境治理实践提供了科学参考,能更好地应对生态系统服务科学与应用的挑战。  相似文献   

16.
中国园林生态学发展综述   总被引:2,自引:0,他引:2       下载免费PDF全文
于艺婧  马锦义  袁韵珏 《生态学报》2013,33(9):2665-2675
运用文献计量等方法对已有科研成果进行统计分析,结果表明:中国近50年园林生态学科领域科研发展经过了起步探索(1962-1981)、缓慢发展(1982-2001)、快速发展(2002-2011)3个时期,园林生态学作为生态学一个新的分支学科,于20世纪90年代末初见端倪,作为一门新兴独立的应用生态学分支学科于21世纪初已基本形成.中国园林生态学领域的研究包括园林生态系统中生物与环境相互作用关系问题、人与环境相互作用关系问题以及园林生态系统与其他生态系统之间相互作用关系问题.当代园林生态研究主要有生态效益研究、生物与环境研究、人的需求与行为研究、生态规划与生态管理研究4个方面,目前园林生态学研究主要侧重生物与环境研究和生态效益研究,两方面的研究成果占总体研究成果的76.3%.不同研究方面也有各自的侧重点,如生物与环境研究侧重对植物的研究,生态效益研究侧重净化环境、水土保持和防灾减灾,生态规划与生态管理研究则侧重生态规划与设计.对四个研究方面的论文主题词检索和高频主题关键词的分布进行统计,结果显示,研究的热点有多样性、群落、水土保持、防灾避险、净化环境、生态规划与设计等.对CNKI中4个研究方面成果中获基金资助项目论文进行统计(不排重),总体成果中基金项目论文所占比重为10.8%,国家和地方基金是园林生态学科研基金资助的主要来源,基金论文比例之和达到85.4%,且国家和地方基金资助论文较多的是“生态与环境研究”和“生态效益研究”,合计占基金论文79.1%.SCI-E中收录的文献基金论文率为47.1%,是CNKI数据库收录的文献基金论文率的4.3倍,且国际基金是基金论文的主要资助来源之一,说明中国园林生态学领域部分科研成果得到国际学界关注.基于CNKI相关主题词统计,“园林生态学”的研究成果只有“景观生态学”的1%,“城市生态学”的8.3%,“园林生态学”学科系统理论研究在相关生态学科研究中所占比重很低,其理论和方法研究还较薄弱.今后在进一步完善学科理论体系、持续开展生态效益和园林植物研究的同时,为更好地研究和解决人-自然复合生态系统问题,提供更多的科学理论支撑,还需拓展交叉生态心理学或环境心理学等其他相关理论,更多地关注人与环境互相作用关系以及生态规划与生态管理等方面的研究,既使环境更好地满足人的行为需求,也使人认识到改变一些行为能更好地保护环境.  相似文献   

17.
景观生态网络研究进展   总被引:33,自引:19,他引:14  
作为生态学重要的概念与方法,生态网络是景观生态学研究的热点问题,也是耦合景观结构、生态过程和功能的重要途径。景观生态网络对于保护生物多样性、维持生态平衡、增加景观连接度具有重要意义。从景观生态网络的相关理论、研究进展、研究方法模型等进行分析,并对其应用前景进行展望,主要介绍了传统景观格局分析、网络分析、模型模拟等方法的适用性与特点,并分析了景观生态网络在城市景观格局优化、自然保护区规划、生物多样性保护、土地规划等领域的应用,最后提出了研究的主要问题。  相似文献   

18.
Pollen dispersal in sugar beet production fields   总被引:1,自引:0,他引:1  
Pollen-mediated gene flow has important implications for biodiversity conservation and for breeders and farmers’ activities. In sugar beet production fields, a few sugar beet bolters can produce pollen as well as be fertilized by wild and weed beet. Since the crop, the wild beets, and the weed beets are the same species and intercross freely, the question of pollen flow is an important issue to determine the potential dispersal of transgenes from field to field and to wild habitats. We report here an experiment to describe pollen dispersal from a small herbicide-resistant sugar beet source towards male sterile target plants located along radiating lines up to 1,200 m away. Individual dispersal functions were inferred from statistical analyses and compared. Pollen limitation, as expected in root-production fields, was confirmed at all the distances from the pollen source. The number of resistant seeds produced by bait plants best fitted a fat-tailed probability distribution curve of pollen grains (power–law) dependent on the distance from the pollen source. A literature survey confirmed that power–law function could fit in most cases. The b coefficient was lower than 2. The number of fertilized flowers by background (herbicide-susceptible) pollen grains was uniform across the whole field. Airborne pollen had a fertilization impact equivalent to that of one adjacent bolter. The individual dispersal function from different pollen sources can be integrated to provide the pollen cloud composition for a given target plant, thus allowing modeling of gene flow in a field, inter-fields in a small region, and also in seed-production area. Long-distance pollen flow is not negligible and could play an important role in rapid transgene dispersal from crop to wild and weed beets in the landscape. The removing of any bolting, herbicide-resistant sugar beet should be compulsory to prevent the occurrence of herbicide-resistant weed beet, thus preventing gene flow to wild populations and preserving the sustainable utility of the resistant varieties. Whether such a goal is attainable remains an open question and certainly would be worth a large scale experimental study.  相似文献   

19.
以佛山为例, 运用实地调查法对亚热带居住区10种常见景观空间夏季微气候指标(风速、温度、湿度)进行实测, 结合居民主观舒适度问卷调查研究成果, 对常见住区景观空间夏季舒适性进行对比分析。结果显示“架空层通风良好处”综合得分最高, 其次为“乔木林下铺装广场”、“露天广场”, 得分最低的为“架空层通风欠佳处”。研究表明亚热带住区景观设计可以通过底层架空并保证良好通风、适当设计多功能露天广场、泳池多功能化、多用乔木少用灌木营造舒朗植物景观等提升夏季舒适度。该研究可为亚热带住区气候适应性景观设计提供一定参考和理论依据。  相似文献   

20.
Recent assertions in the literature (e.g., Keller et al. 2015) suggest that landscape genetic research has been infrequently applied by practitioners. We were interested to test this assertion, which is difficult to assess, since applications may not be detectable through searches of peer-reviewed literature. Producing publications may not be a goal of practitioners. We developed a method to search the internet for evidence of research applications and evaluated 25 different research fields in the natural sciences. We found that fields with more publications also had more applications, but the field of landscape genetics was less applied than expected based on the number of peer-reviewed publications—only about 4 % of landscape genetics articles were applied. In fact, all research fields in genetics or evolutionary biology were under-applied compared to ‘whole organism’, ecological research fields. This result suggests the lack of applications in landscape genetics may be due to a systemic under-application of genetics research, perhaps related to a lack of understanding of genetics by practitioners. We did find some evidence of landscape genetic applications however, which we sorted into 5 categories: (1) identification of evolutionarily significant units for conservation, (2) managing pathogens and invasive species, (3) natural heritage systems planning, (4) assessing population status, and (5) restoration of populations.  相似文献   

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